Installation Guide

Underdeck Systems Installation Guide

STEP 3: PROPER CAULK AND FLASHING SYSTEM

1. Successful installation of your deck is dependent on proper sealing

and flashing at the surfaces where the deck meets your home or

other structure. Water must be properly diverted to avoid leakage.

2. The trim flashing included will be bent to divert water into the panels

around the entire inside perimeter of your deck. You must remain

above the 2x2 framing already in place to allow the water to be

diverted to the panels.

3. Using the GECEL2300 provided, seal the edges of the flashing for the

entire perimeter. Attach Under Deck flashing on all sides of the deck

that are connected to the structure. Under Deck water diverters or

flashing should be installed at the ledger board between each joist to

ensure water run-off at ledger. Place a bead of GEOCEL2300

waterproof caulk along top edge where water diverter meets the

joist.

4. If you have a cantilever on your deck, you will want to install flashing

that covers the beam, diverting the water to the inside or larger side

of the cantilever.

5. Check to make certain that the proper flashing has been installed on

the deck when it was built. If not, additional flashing will ne

necessary.

STEP 4: GUTTER INSTALLATION

1. The gutter will be mounted against the beam (if there is a cantilever)

or against a treated 2x4 nailed to the inside of the outside posts.

Level from the framing to the beam and snap a line. If using a 2x4,

level to the posts and snap a line. Attach the 2x4 to the posts on the

line.

2. Attach the gutter to this line using the enclosed gutter hangers,

mounted with 1 ¼ galvanized screws. Space the hangers about 4 feet

apart, placing one at each end.

STEP 5: PREPARING THE PANELS FOR INSTALLATION

1. Measure the distance from the ledger board to the half-way point of

the gutter. This will be the panel length.

2. You must make the box end on the house side, and the drain slope on

the gutter end.

3. Keep the interlocking panels consistent avoiding errors in bending

and cutting the wrong end. The Panel end that will be placed toward

the ledger board (for outside gutter install) will be boxed and all

bends sealed to prevent leaks. Do this by cutting the frame of the

panel ¾” from the end, bend up the wing and caulk in the corners to

prevent leaking.

4. The opposite end will drain into the gutter and must be bent down

slightly to allow the water to drain. Do this by removing ½” of the

frame, bend the wing down using a hand brake.

Panel end at house

Panel end for gutter